Ivan Chytra

Intraoperative fluid optimization using stroke volume variation in high risk surgical patients: results of prospective randomized study

IntroductionStroke volume variation (SVV) is a good and easily obtainable predictor of fluid responsiveness, which can be used to guide fluid therapy in mechanically ventilated patients. During major abdominal surgery, inappropriate fluid management may result in occult organ hypoperfusion or fluid overload in patients with compromised cardiovascular reserves and thus increase postoperative morbidity. The aim of our study was to evaluate the influence of SVV guided fluid optimization on organ functions and postoperative morbidity in high risk patients undergoing major abdominal surgery.MethodsPatients undergoing elective intraabdominal surgery were randomly assigned to a Control group (n = 60) with routine intraoperative care and a Vigileo group (n = 60), where fluid management was guided by SVV (Vigileo/FloTrac system). The aim was to maintain the SVV below 10% using colloid boluses of 3 ml/kg. The laboratory parameters of organ hypoperfusion in perioperative period, the number of infectious and organ complications on day 30 after the operation, and the hospital and ICU length of stay and mortality were evaluated. The local ethics committee approved the study.ResultsThe patients in the Vigileo group received more colloid (1425 ml [1000-1500] vs. 1000 ml [540-1250]; P = 0.0028) intraoperatively and a lower number of hypotensive events were observed (2[1-2] Vigileo vs. 3.5[2-6] in Control; P = 0.0001). Lactate levels at the end of surgery were lower in Vigileo (1.78 ± 0.83 mmol/l vs. 2.25 ± 1.12 mmol/l; P = 0.0252). Fewer Vigileo patients developed complications (18 (30%) vs. 35 (58.3%) patients; P = 0.0033) and the overall number of complications was also reduced (34 vs. 77 complications in Vigileo and Control respectively; P = 0.0066). A difference in hospital length of stay was found only in per protocol analysis of patients receiving optimization (9 [8-12] vs. 10 [8-19] days; P = 0.0421). No difference in mortality (1 (1.7%) vs. 2 (3.3%); P = 1.0) and ICU length of stay (3 [2-5] vs. 3 [0.5-5]; P = 0.789) was found.ConclusionsIn this study, fluid optimization guided by SVV during major abdominal surgery is associated with better intraoperative hemodynamic stability, decrease in serum lactate at the end of surgery and lower incidence of postoperative organ complications.Trial registrationCurrent Controlled Trials ISRCTN95085011.

Esophageal Doppler-guided fluid management decreases blood lactate levels in multiple-trauma patients: a randomized controlled trial

IntroductionEsophageal Doppler was confirmed as a useful non-invasive tool for management of fluid replacement in elective surgery. The aim of this study was to assess the effect of early optimization of intravascular volume using esophageal Doppler on blood lactate levels and organ dysfunction development in comparison with standard hemodynamic management in multiple-trauma patients.MethodsThis was a randomized controlled trial. Multiple-trauma patients with blood loss of more than 2,000 ml admitted to the intensive care unit (ICU) were randomly assigned to the protocol group with esophageal Doppler monitoring and to the control group. Fluid resuscitation in the Doppler group was guided for the first 12 hours of ICU stay according to the protocol based on data obtained by esophageal Doppler, whereas control patients were managed conventionally. Blood lactate levels and organ dysfunction during ICU stay were evaluated.ResultsEighty patients were randomly assigned to Doppler and 82 patients to control treatment. The Doppler group received more intravenous colloid during the first 12 hours of ICU stay (1,667 ± 426 ml versus 682 ± 322 ml; p < 0.0001), and blood lactate levels in the Doppler group were lower after 12 and 24 hours of treatment than in the control group (2.92 ± 0.54 mmol/l versus 3.23 ± 0.54 mmol/l [p = 0.0003] and 1.99 ± 0.44 mmol/l versus 2.37 ± 0.58 mmol/l [p < 0.0001], respectively). No difference in organ dysfunction between the groups was found. Fewer patients in the Doppler group developed infectious complications (15 [18.8%] versus 28 [34.1%]; relative risk = 0.5491; 95% confidence interval = 0.3180 to 0.9482; p = 0.032). ICU stay in the Doppler group was reduced from a median of 8.5 days (interquartile range [IQR] 6 to16) to 7 days (IQR 6 to 11) (p = 0.031), and hospital stay was decreased from a median of 17.5 days (IQR 11 to 29) to 14 days (IQR 8.25 to 21) (p = 0.045). No significant difference in ICU and hospital mortalities between the groups was found.ConclusionOptimization of intravascular volume using esophageal Doppler in multiple-trauma patients is associated with a decrease of blood lactate levels, a lower incidence of infectious complications, and a reduced duration of ICU and hospital stays.

Clinical and microbiological efficacy of continuous versus intermittent application of meropenem in critically ill patients: a randomized open-label controlled trial

IntroductionMeropenem bactericidal activity depends on the time when the free drug concentrations remain above the minimum inhibitory concentration of pathogens. The goal of this study was to compare clinical and bacteriological efficacy of continuous meropenem infusion versus bolus administration in critically ill patients with severe infection, and to evaluate the safety of both dosing regimens.MethodsPatients admitted to the interdisciplinary Intensive Care Unit (ICU) who suffered from severe infections and received meropenem were randomized either in the Infusion group (n = 120) or in the Bolus group (n = 120). Patients in the Infusion group received a loading dose of 2 g of meropenem followed by a continuous infusion of 4 g of meropenem over 24 hours. Patients in the Bolus group were given 2 g of meropenem over 30 minutes every 8 hours. Clinical and microbiological outcome, safety, meropenem-related length of ICU and hospital stay, meropenem-related length of mechanical ventilation, duration of meropenem treatment, total dose of meropenem, and ICU and in-hospital mortality were assessed.ResultsClinical cure at the end of meropenem therapy was comparable between both groups (83.0% patients in the Infusion vs. 75.0% patients in the Bolus group; P = 0.180). Microbiological success rate was higher in the Infusion group as opposed to the Bolus group (90.6% vs. 78.4%; P = 0.020). Multivariate logistic regression identified continuous administration of meropenem as an independent predictor of microbiological success (OR = 2.977; 95% CI = 1.050 to 8.443; P = 0.040). Meropenem-related ICU stay was shorter in the Infusion group compared to the Bolus group (10 (7 to 14) days vs. 12 (7 to 19) days; P = 0.044) as well as shorter duration of meropenem therapy (7 (6 to 8) days vs. 8 (7 to 10) days; P = 0.035) and lower total dose of meropenem (24 (21 to 32) grams vs. 48 (42 to 60) grams; P < 0.0001). No severe adverse events related to meropenem administration in either group were observed.ConclusionsContinuous infusion of meropenem is safe and, in comparison with higher intermittent dosage, provides equal clinical outcome, generates superior bacteriological efficacy and offers encouraging alternative of antimicrobial therapy in critically ill patients.

Fluid management guided by a continuous non-invasive arterial pressure device is associated with decreased postoperative morbidity after total knee and hip replacement

BackgroundThe use of goal directed fluid protocols in intermediate risk patients undergoing hip or knee replacement was studied in few trials using invasive monitoring. For this reason we have implemented two different fluid management protocols, both based on a novel totally non-invasive arterial pressure monitoring device and compared them to the standard (no-protocol) treatment applied before the transition in our academic institution.MethodsThree treatment groups were compared in this prospective study: the observational (CONTROL, N = 40) group before adoption of fluid protocols and two randomized groups after the transition to protocol fluid management with the use of the continuous non-invasive blood pressure monitoring (CNAP®) device. In the PRESSURE group (N = 40) standard variables were used for restrictive fluid therapy. Goal directed fluid therapy using pulse pressure variation was used in the GDFT arm (N = 40). The influence on the rate of postoperative complications, on the hospital length of stay and other parameters was assessed.ResultsBoth protocols were associated with decreased fluid administration and maintained hemodynamic stability. Reduced rate of postoperative infection and organ complications (22 (55 %) vs. 33 (83 %) patients; p = 0.016; relative risk 0.67 (0.49–0.91)) was observed in the GDFT group compared to CONTROL. Lower number of patients receiving transfusion (4 (10 %) in GDFT vs. 17 (43 %) in CONTROL; p = 0.005) might contribute to this observation. No significant differences were observed in other end-points.ConclusionIn our study, the use of the fluid protocol based on pulse pressure variation assessed using continuous non-invasive arterial pressure measurement seems to be associated with a reduction in postoperative complications and transfusion needs as compared to standard no-protocol treatment.Trial registrationACTRN12612001014842

The impact of general versus local anesthesia on early subclinical cognitive function following carotid endarterectomy evaluated using P3 event-related potentials

BackgroundPostoperative cognitive dysfunction (POCD) is detected in 25% of patients undergoing carotid endarterectomy (CEA). The mechanism of POCD is poorly understood, but it is believed that general anesthesia (GA) itself may contribute significantly to POCD. The aim of our prospective study was to compare, with the aid of event-related potentials, the impact of general anesthesia (GA) and local anesthesia (LA) on POCD in patients undergoing CEA.MethodsSixty patients were included in this study and were divided into two groups: CEA was performed in 30 patients placed under GA (total intravenous anesthesia), herein the GA group, while 30 patients underwent CEA under LA (cervical plexus block), herein LA group. Cognitive outcome was assessed with the use of auditory event-related potentials (ERPs), P3 response. The measurements were taken before surgery (pre-op) and on the first (1.post-op) and the sixth postoperative days (6.post-op).ResultsPreoperative cognitive functions did not differ significantly between the two groups. A significant decrease in P3 amplitude was found on the first postoperative day (1.post-op) in the GA group (p = 0.0005), but normalization of P3 amplitude was detected at the second postoperative measurement (6.post-op). The patients operated on under local anesthesia (LA group) showed stable P3 amplitudes in all three measurements. No significant changes in P3 latencies were observed in either group. There were no significant differences between the two groups regarding demographic characteristics, preoperative and postoperative clinical condition, percentage significance of carotid artery stenosis, duration of carotid cross-clamping or in the frequency of shunt use (zero frequency for both groups).ConclusionsOur study showed that general anesthesia, used for patients undergoing CEA, negatively influenced cognitive function during the immediate period after surgery (the first postoperative day). However, by the sixth postoperative day, this cognitive impairment was no longer being detected. POCD occurring shortly after carotid endarterectomy is the result of general anesthesia, which is probably an independent evoking factor in itself. The cognitive deficit recorded only during the immediate postoperative period, is not a negative effect of GA but merely a side-effect and thus GA should not be considered inferior to LA for use during CEA.

Cost analysis of the stroke volume variation guided perioperative hemodynamic optimization – an economic evaluation of the SVVOPT trial results

BackgroundPerioperative goal directed therapy (GDT) can substantially improve the outcomes of high risk surgical patients as shown by many clinical studies. However, the approach needs initial investment and can increase the already very high staff workload. These economic imperatives may be at least partly responsible for weak adherence to the GDT concept. A few models are available for the evaluation of GDT cost-effectiveness, but studies of real economic data based on a recent clinical trial are lacking. In order to address this we have performed a retrospective analysis of the data from the “Intraoperative fluid optimization using stroke volume variation in high risk surgical patients” trial (ISRCTN95085011).MethodsThe health-care payers perspective was used in order to evaluate the perioperative hemodynamic optimization costs. Hospital invoices from all patients included in the trial were extracted. A direct comparison between the study (GDT, N = 60) and control (N = 60) groups was performed. A cost tree was constructed and major cost drivers evaluated.ResultsThe trial showed a significant improvement in clinical outcomes for GDT treated patients. The mean cost per patient were lower in the GDT group 2877 ± 2336€ vs. 3371 ± 3238€ in controls, but without reaching a statistical significance (p = 0.596). The mean cost of all items except for intraoperative monitoring and infusions were lower for GDT than control but due to the high variability they all failed to reach statistical significance. Those costs associated with clinical care (68 ± 177€ vs. 212 ± 593€; p = 0.023) and ward stay costs (213 ± 108€ vs. 349 ± 467€; p = 0.082) were the most important differences in favour of the GDT group.ConclusionsIntraoperative fluid optimization with the use of stroke volume variation and Vigileo/FloTrac system showed not only a substantial improvement of morbidity, but was associated with an economic benefit. The cost-savings observed in the overall costs of postoperative care trend to offset the investment needed to run the GDT strategy and intraoperative monitoring.Trial registrationISRCTN95085011

Balanced study groups in a randomized trial--authors' response.

A ballanced distribution between study and intervention group could be observed in our randomized prospective trial. This raised a comment and request by dr.Munis to clarify the randomizatio process. Besides answering this request we conclude that also another factors could contribute to this ballanced distribution.

Quality of life 1 year after intensive care

The aim of our study was the comparison of quality of life before admission to the ICU and 1 year after the discharge from ICU.